Abstract Using the Hubble space Telescope Fine Guidance Sensor,
we have measured the trigonometric parallax of the bright cataclysmic
variable 1223 Sgr. The absolute parallax is
mas, making V1223 Sgr the most distant CV with a
well-determined trigonometric parallax. This distance, a Lutz-Kelker
correction, and the previously measured extinction yield an absolute
visual high-state magnitude
. We outline a
model, which is consistent with the observed spin-down of the white
dwarf and provides for much of the UV/optical emission by
reverberation of X-rays. From previous X-ray and UV/optical
data, we derive an accretion luminosity
erg s
-1, a white dwarf mass
, and an accretion rate
g s
-1,